gpio/mpc83xx_spisel_boot.c: gpio driver for SPISEL_BOOT signal
Some SoCs in the mpc83xx family, e.g. mpc8309, have a dedicated spi
chip select, SPISEL_BOOT, that is used by the boot code to boot from
flash.
This chip select will typically be used to select a SPI boot
flash. The SPISEL_BOOT signal is controlled by a single bit in the
SPI_CS register.
Implement a gpio driver for the spi chip select register. This allows a
spi driver capable of using gpios as chip select, to bind a chip select
to SPISEL_BOOT.
It may be a little odd to do this as a GPIO driver, since the signal
is neither GP or I, but it is quite convenient to present it to the
spi driver that way. The alternative it to teach mpc8xxx_spi to handle
the SPISEL_BOOT signal itself (that is how it's done in the linux
kernel, see commit 69b921acae8a)
Signed-off-by: Klaus H. Sorensen <khso@prevas.dk>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
diff --git a/drivers/gpio/mpc83xx_spisel_boot.c b/drivers/gpio/mpc83xx_spisel_boot.c
new file mode 100644
index 0000000..c7b0840
--- /dev/null
+++ b/drivers/gpio/mpc83xx_spisel_boot.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2019 DEIF A/S
+ *
+ * GPIO driver to set/clear SPISEL_BOOT pin on mpc83xx.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <mapmem.h>
+#include <asm/gpio.h>
+
+struct mpc83xx_spisel_boot {
+ u32 __iomem *spi_cs;
+ ulong addr;
+ uint gpio_count;
+ ulong type;
+};
+
+static u32 gpio_mask(uint gpio)
+{
+ return (1U << (31 - (gpio)));
+}
+
+static int mpc83xx_spisel_boot_direction_input(struct udevice *dev, uint gpio)
+{
+ return -EINVAL;
+}
+
+static int mpc83xx_spisel_boot_set_value(struct udevice *dev, uint gpio, int value)
+{
+ struct mpc83xx_spisel_boot *data = dev_get_priv(dev);
+
+ debug("%s: gpio=%d, value=%u, gpio_mask=0x%08x\n", __func__,
+ gpio, value, gpio_mask(gpio));
+
+ if (value)
+ setbits_be32(data->spi_cs, gpio_mask(gpio));
+ else
+ clrbits_be32(data->spi_cs, gpio_mask(gpio));
+
+ return 0;
+}
+
+static int mpc83xx_spisel_boot_direction_output(struct udevice *dev, uint gpio, int value)
+{
+ return 0;
+}
+
+static int mpc83xx_spisel_boot_get_value(struct udevice *dev, uint gpio)
+{
+ struct mpc83xx_spisel_boot *data = dev_get_priv(dev);
+
+ return !!(in_be32(data->spi_cs) & gpio_mask(gpio));
+}
+
+static int mpc83xx_spisel_boot_get_function(struct udevice *dev, uint gpio)
+{
+ return GPIOF_OUTPUT;
+}
+
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+static int mpc83xx_spisel_boot_ofdata_to_platdata(struct udevice *dev)
+{
+ struct mpc8xxx_gpio_plat *plat = dev_get_platdata(dev);
+ fdt_addr_t addr;
+ u32 reg[2];
+
+ dev_read_u32_array(dev, "reg", reg, 2);
+ addr = dev_translate_address(dev, reg);
+
+ plat->addr = addr;
+ plat->size = reg[1];
+ plat->ngpios = dev_read_u32_default(dev, "ngpios", 1);
+
+ return 0;
+}
+#endif
+
+static int mpc83xx_spisel_boot_platdata_to_priv(struct udevice *dev)
+{
+ struct mpc83xx_spisel_boot *priv = dev_get_priv(dev);
+ struct mpc8xxx_gpio_plat *plat = dev_get_platdata(dev);
+ unsigned long size = plat->size;
+ ulong driver_data = dev_get_driver_data(dev);
+
+ if (size == 0)
+ size = 0x04;
+
+ priv->addr = plat->addr;
+ priv->spi_cs = map_sysmem(plat->addr, size);
+
+ if (!priv->spi_cs)
+ return -ENOMEM;
+
+ priv->gpio_count = plat->ngpios;
+
+ priv->type = driver_data;
+
+ return 0;
+}
+
+static int mpc83xx_spisel_boot_probe(struct udevice *dev)
+{
+ struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+ struct mpc83xx_spisel_boot *data = dev_get_priv(dev);
+ char name[32], *str;
+
+ mpc83xx_spisel_boot_platdata_to_priv(dev);
+
+ snprintf(name, sizeof(name), "MPC@%lx_", data->addr);
+ str = strdup(name);
+
+ if (!str)
+ return -ENOMEM;
+
+ uc_priv->bank_name = str;
+ uc_priv->gpio_count = data->gpio_count;
+
+ return 0;
+}
+
+static const struct dm_gpio_ops mpc83xx_spisel_boot_ops = {
+ .direction_input = mpc83xx_spisel_boot_direction_input,
+ .direction_output = mpc83xx_spisel_boot_direction_output,
+ .get_value = mpc83xx_spisel_boot_get_value,
+ .set_value = mpc83xx_spisel_boot_set_value,
+ .get_function = mpc83xx_spisel_boot_get_function,
+};
+
+static const struct udevice_id mpc83xx_spisel_boot_ids[] = {
+ { .compatible = "fsl,mpc8309-spisel-boot" },
+ { .compatible = "fsl,mpc83xx-spisel-boot" },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(spisel_boot_mpc83xx) = {
+ .name = "spisel_boot_mpc83xx",
+ .id = UCLASS_GPIO,
+ .ops = &mpc83xx_spisel_boot_ops,
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+ .ofdata_to_platdata = mpc83xx_spisel_boot_ofdata_to_platdata,
+ .platdata_auto_alloc_size = sizeof(struct mpc8xxx_gpio_plat),
+ .of_match = mpc83xx_spisel_boot_ids,
+#endif
+ .probe = mpc83xx_spisel_boot_probe,
+ .priv_auto_alloc_size = sizeof(struct mpc83xx_spisel_boot),
+};